Field of the Disclosure
Various embodiments relate to wireless communications methods and apparatus and, more particularly, to wireless communications methods and apparatus that facilitate discovery of small coverage area base stations in communications systems.
Description of Related Art
Various user equipment (UE) devices, e.g., smartphones and other mobile communications devices, today are equipped with multiple modems that support a variety of technologies such as, e.g., LTE (Long Term Evolution), HSPA (High Speed Packet Access), Wifi, Bluetooth, etc. These technologies typically operate in different bands. Long term evolution (LTE) itself supports operation in multiple bands (carriers) to increase the data rates. LTE macro cell base station communications operate in a primary band while LTE small coverage area base stations may be deployed to use bands that are different from the primary band of the macro cells. In the near future LTE may also have LTE-WiFi aggregation for traffic offload.
In a system where a variety of different base stations are deployed including macro cellular base stations and small coverage area base stations including e.g., LTE femto cell base stations, WiFi access points, and/or Bluetooth APs, it would be beneficial if a UE device was able to discover the various small coverage area base stations deployed in different bands and/or using different technologies, in addition to being able to discover the macro cell base stations, to determine the best or most suitable interface to use for traffic. Most of the different technologies have different discovery mechanisms. Typically to discover a particular type of small coverage area base station, which uses a different technology than the used by the macro cell base station, the UE device needs to activate a particular modem corresponding to the technology and needs to keep searching for that type of small cell base station. Thus to search for both WiFi access points and Bluetooth APs, the UE device may need to active both types of modems and search using both types of modems. In the case of asynchronous technologies such as WiFi and Bluetooth, the search increases power consumption of the UE significantly and hampers the battery life, given that the UE devices have limited battery power and scanning for small coverage area base stations operating in various frequency bands can consume a significant amount of battery power. In the case where the deployed macro cells use LTE and at least some deployed small cell base stations, e.g., femto cells, also use LTE, the small cell base stations using LTE typically transmit in their respective bands, and the UE needs to tune to different bands to discover the different small cell base stations. During the time of searching for the small coverage area LTE base stations, the UE normally is not communicating with its macro base station, e.g., its eNB, in the macro cell in which the UE is located. This results in loss of throughput for an active UE.
In view of the above discussion it should be appreciated that there is a need for methods and/or apparatus which can facilitate efficient discovery of small coverage area base stations, e.g., femto cell base stations, pico cell base stations, WiFi access points, Bluetooth access points, etc. It would be desirable if the methods and/or apparatus are power efficient, reduce the time for discovering the set of small coverage area base stations in an area, and/or reduce the amount of overhead signaling over current approaches, thus improving throughput and/or reducing the amount of UE device battery drain expended for small coverage area base station searches.